dell-esrt: Improve the experience for the plugin (Closes: #1245)
dell-esrt: Improve the experience for the plugin (Closes: #1245)

* Set UpdateError to indicate how the device needs to be updated
* Set the device as needing reboot
* If admin password is set show the message to frontend via `UpdateError`

fwupd/fwupd,hughsie/fwupd,hughsie/fwupd,hughsie/fwupd,fwupd/fwupd,fwupd/fwupd,fwupd/fwupd,hughsie/fwupd